<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
     .one
     {
        width: 1000px;
        height: 600px;
        margin: 170px auto;
        position: relative;
        background-image: url(imag/1g.jpg);
        background-repeat: no-repeat;
        background-size: cover;
     }
     div:hover span /*鼠标悬停在div元素中span 元素会应用下列样式 有空格*/
     {
        display: inline-block;
        width: 50px;
        height: 80px;
        color: white;
        font-size: 70px;
        line-height: 80px;
        text-align: center;
        background-color: black;
        opacity: 0.8;

       
     }
   div:hover .two/*鼠标悬停在div元素中.two所指元素会应用下列样式，hover与two有空格*/
     {
        display:block;
        position: absolute;
        top: 280px;
        left: 0px;
     }
     div:hover .three/*鼠标悬停在div元素中.two所指元素会应用下列样式，hover与three有空格*/
     {
        display:block;
        position: absolute;
        top: 280px;
        right: 0px;
     }
     .four
     {
        width: 986px;
        height: 40px;
        position: absolute;
        bottom: 0px;
        left: 0px;
        color: white;
        background-color: black;
        opacity: 0.7;
        padding-left: 20px;
        font-size: 25px;
        padding-top: 5px;
       
     }
     .five{
        width: 1000px;
        height: 600px;
        position: absolute;
        top: 0px;
        left: 0px;
     }
     div:hover .five /*蒙版*/
     {
         background-color: black;
         opacity: 0.2;
     }

    </style>
</head>
<body>
    <div class="one">
        <span class="two">&lt</span>
        <span class="three">&gt</span>
        <div class="four">海外风光</div>
        <div class="five"></div>
     </div>
</body>
</html>